a(n) = 280*binomial(n+4,9) + 280*binomial(n+4,8) + 105*binomial(n+3,7) + 77*binomial(n+3,6) + 43*binomial(n+2,5) - 16*binomial(n+2,4) + 20*binomial(n+1,3) - floor(n*(n^2 - 1)*(n^2 - 4)*(n-3)/360).

A064204

a(n) = 280*binomial(n+4,9) + 280*binomial(n+4,8) + 105*binomial(n+3,7) + 77*binomial(n+3,6) + 43*binomial(n+2,5) - 16*binomial(n+2,4) + 20*binomial(n+1,3) - floor(n*(n^2 - 1)*(n^2 - 4)*(n-3)/360).

Terms

    a(0) =0a(1) =0a(2) =4a(3) =120a(4) =1140a(5) =6525a(6) =27580a(7) =94724a(8) =279160a(9) =730930a(10) =1741300a(11) =3839660a(12) =7937644a(13) =15535975a(14) =29012620a(15) =52014200a(16) =89976240a(17) =150801764a(18) =245731940a(19) =390446960a(20) =606440100a(21) =922712945a(22) =1377845084a(23) =2022497180a(24) =2922412200a(25) =4161985750a(26) =5848482900a(27) =8116985604

External references